Keyhole-guard



(N0 Mqdel.)

L. SCHNEIDER. K'BYHULE GUARD.

No 5051299' Patented Sept. 19,1893,

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5f: l I l i Y .//fgyaf UNITED STATES PATENT Errea.

LOUIS SCHNEIDER, OF WILLIAMSPORT, PENNSYLVANIA.

KEYHoLE-GUARD.

SPECIFICATION forming part of Letters Patent No. 505,299, `dated September 19, 1893.

Application filed January 14, 1893. Serial No. 458,353. (No model.)

.To a/ZZ whom it may concern:

Be it known that I, LOUIS SCHNEIDER, a citizen of the United States, residing at Williamsport, in the county of Lycoming and State of Pennsylvania, have invented a certain new and useful Improvement in Keyhole-Guards, of which the following is a specification.

My improved key-hole guard is adapted to match in the key-hole of any ordinary lock, and to serve as a conveniently applicable guard for obstructing the sight through the key-hole and for preventing the use of any' key by unauthorized persons. It may apply on the door of a room or abuilding, either on the inside or outside thereof. I will describe it as applied to the inside of a door of an apartment having an ordinary keyhole eX- tending through in a straight line. y

The accompanying drawings form a part of this specification and represent what I consider the best means of carrying out the invention.

Figure 1 is an elevation partly in vertical section showing my guard in use. The remaining figures are on a larger scale. Fig. 2 is a face view with the cover plate removed. Fig. 3 is a side elevation of the key. Figs. 4 and 5 are edge views of the guard. Fig. 6 is an end elevation of a portion, and Fig. 7 is an end view of the key.

Similar letters of reference indicate corresponding parts in all the figures where they appear. f

A is the main body of the casing, certain portions being designated when necessary by super-numerals, as A.

B is the covering plate of the case, secured to the part A by rivets A', A', which extend upward from the bodyA and are received in corresponding holes in the cover-plate B, to strongly hold the cover and maintain the true positions of the parts.

A2 is a nicely cut screw lying horizontally in the center of the part A, and connected rigidly thereto by a post A3.

G is a cone properly tapped and fitted as a nut on said screw, the small end being toward the post A3, and the large end being scored, as indicated by g to receive the wings of a key and allow it to be turned thereby, as will appear farther on.

D D are iiat levers pivoted on separate rivets A A', and extending outward through sufficient slots a a, in the opposite edge of the casing.

E E are springs secured respectively in the levers D D, which springs acting against a convenient abutting surface in the casing A, urge the levers D D together.

M is a k ey having wings M M on the front of its tubular shank, adapted to engage in the scores q g in the nut G and turn it. A key-hole a is provided in the casing A of proper form to admit this key. The shank o f the key is of such length and the construction of the parts in the interior of the lock are such as to allow this key to be revolved and to follow the cone G as it is traversed down the screw by the rotation received through the key. As it moves its conical surface presses against the adjacent inner edges of the levers D D and urges them apart. The hooks on the levers engage in the interior of the ordinary lock K, and prevent their removal until my key M shall be again used to rotate the cone G in the opposite direction, and allow the levers D to again spring together. The levers D D should be of sufficient length to extend a sufficient distance into the lock to prevent the insertion and operating of akey from the opposite side of the door. It therefore guards effectually against the intrusion of parties from without. It is obvious that my guard may also serve to obstruct, though less effectually, the operating of a key by any unauthorized parties from the same side to which the guard is applied. That is to say, if the occupant of a room on going out, after locking the door, and removing thekey, inserts this guard, and by itsI key M drives the conical nut G forward and eX- tends the levers D, no one can unlock the door until the guard is removed. No ordinary intruder would be likely to have the facilities and skill for introducing Wires or other devices through the key-hole o. and turning the cone G, which is necessary to remove my guard before operating the ordinary lock to open the door. When the proper occupant of the room returns the key M being inserted the guard is removed easily. Where, as in many cases, a key-hole opens only on one side of the door, the device can still be applied in that manner.

Moditications may be made in the details Without departing from the principle or sacricing the advantages of the invention. I can vary the number and arrangement of the hooks on the levers D. The slight notches d, which are adapted to engage the casin g of the lock adjacent to the key-hole, may be omitted, or if such notches are employed and engaged reliably With the casing of the lock, the hooks nearer the ends of the levers may be omitted. It is important that one or both of the levers D D shall extend sufficiently in- Ward to prevent the insertion of the ordinary key or even a skeleton key from the opposite side of the door. The casing may be made in more than two parts. The parts may be secured together by other means than those shown. The scores in the nut G may be varied in size and arrangement, the key being correspondingly modified, so that the diversities in the guards and keys Will tend by Wellknown principles, to prevent the use of any but the proper key in removing the guard.

I have shown the nut as of conical shape, and prefer such, but do not conne the in vention thereto. It is obvious that spheroidal or other forms may be used, taking care to propsprings E E on opposite sides of the nut, in

combination with each other and With the key M and provisions as the Wings h on the key and score g on the nut for engaging these parts to open and close the levers, all arranged for joint operation substantially as herein specified.

In testimony that I claim the invention above set forth I affix my signature in presence of two Witnesses.

LOUIS SCHNEIDER.

Vitnesses:

F. H. McOoRMIcK, CARL HERDIC. 

